1. Field of the Invention
This invention generally relates to energy management and, more particularly, to a system and method for efficiently managing peak power consumption using stored energy.
2. Description of the Related Art
The higher cost of energy is being addressed by the consumer in the form of more efficient energy consumption devices and consumption algorithms that economize. Power utilities and government agencies often attempt to address the issue by changing the consumer's usage habits. Rather than following market-based principles that might dictate that a larger consumer receive a discounted rate, policies may be based upon the assumption that it is fair to impose a proportionally greater charge to users that consume more energy. One such approach is to establish power consumption tiers, and increase the cost of power over a billing cycle as the consumer's usage advances over the tiers. Another approach often applied to commercial users is to determine energy costs based on peak power usage, and bill the user for the total amount of energy used during the billing period at the peak power rate.
Due to higher energy costs in general, and policy-driven cost algorithms, many consumers, especially commercial users, have installed energy storage devices in the local system, such as a battery. To address the above-mentioned peak usage billing, the consumer may add energy into storage at night, when overall power usage is lower and prices are cheaper. Then, this stored energy can be used in the daytime when the user's consumption demands are the greatest. Unfortunately, peak power usage cannot always be predicted. For example, the user may be a multi-residential facility, and peak power (e.g., AC power) may be associated with temperature, which is hard to predict. Further, there is a cycling cost penalty associated with the use of stored energy. The more often stored energy is cycled, the more quickly the storage device wears out. Based upon the cycling cost penalty and the unpredictability of peak usage, it is often against the user's interest to use an algorithm that simply cycles stored power on a daily basis.
Other users have energy generation equipment, such as photovoltaic (PV) or wind turbines, to augment their local systems. However, there are no known systems with an integrated approach to PV, storage, and load management.
It would be advantageous if peak power usage could be accurately predicted, so that stored energy could be efficiently used to supplement the input power supplied by a public utility.